# Math Help - use suitable substitution to integrate

1. ## use suitable substitution to integrate

would be much grateful for help with the following 2 problems.

use suitable substitution to integrate

(a) $f(x) = x^2 (x^2 - 10)^{20}$

(b) $f(t) = t^2 e^{3t^3+5}$

2. Originally Posted by decoy808

(b) $f(t) = t^2 e^{3t^3+5}$
$u = 3t^3+5$

3. Originally Posted by decoy808
(a) $f(x) = x^2 (x^2 - 10)^{20}$
Try this : $u=x^2-10$